Northern Ireland’s main political parties have been challenged by the DUP to name their major donors.

Sir Jeffrey Donaldson threw down the gauntlet after his party revealed who had given them

a £425,000 donation that bankrolled its pro-Brexit campaign.

And the MP, who was the DUP’s national campaign director for Brexit, has now shone the torch on to other parties.

He queried, for instance, how Sinn Fein had spent more than $12m raised by the US-based Friends of Sinn Fein group, and also raised questions about use of donors by the SDLP and UUP.

Sinn Fein responded to Sir Jeffrey’s challenge, saying: “Any money raised in the USA by Friends of Sinn Fein is registered with the US Justice Department.

“Accounts are produced twice a year and all donations over $50 are published.

“The names of donors to Friends of Sinn Fein have been widely published in US and Irish media.”

The Belfast Telegraph revealed yesterday how the Constitutional Research Council (CRC), a group of pro-Union business people led by a Conservative Party member, had made the £425,622 donation to the DUP.

Yesterday it was reported the CRC was preparing to invest even more into politics, this time with opponents of Scottish nationalists in the event of Scotland’s First Minister Nicola Sturgeon calling a second independence referendum.

Senior Sinn Fein representative Conor Murphy turned the heat back on the DUP, saying it was still not clear who belonged to the CRC, and what it got in return.

He said: “Instead we have the name of a secretive body, no list of members and donors. It now appears that the DUP spent at least £370,000 on newspaper advertisements and campaign materials in Britain where they don’t stand for election. “This raises serious questions about transparency.”

Alliance has called on the DUP — and all other parties — to voluntarily identify their donors so voters can judge whether they have been influenced.

Last night, as claims by multi- millionaire pro-Brexit banker

Arron Banks that the DUP demanded money to support him also resurfaced, Alliance leader Naomi Long said it raised serious questions.

“Would the DUP have campaigned as vigorously for Brexit had they not received a large donation to do so?” she asked.

“How does that set against the previous allegations by Arron Banks that they were essentially charging a fee to join a Leave campaign?

“All of those questions need to be answered and answered openly.”

The DUP has denied the allegations in a book called The Bad Boys Of Brexit by Mr Banks, who poured millions of pounds into the campaign for the UK to leave the EU.

Mrs Long added: “The DUP said in 2014 and 2016 they would release all of their donor information — they didn’t do it.

“The Brexit campaign sold voters a lie about the influence of faceless EU bureaucrats, but now it appears faceless donors were pulling the strings of the campaign.

“Any pretence security concerns were the only reason the DUP did not follow through on previous pre-election commitments in 2014 and 2016 to move to full transparency are exposed as the smokescreen they are, given the chair of this group was Scottish.”

Mrs Long was referring to the chairman of the group, Richard Cook, a prominent Scottish Conservative figure who has stood as a parliamentary candidate in several elections, and blogged in 2010 that he was a director of the think tank Think Scotland.

Mr Cook — who reportedly also founded a company called Five Star Investment Management Ltd with the former head of the Saudi Arabian intelligence agency, Prince Nawwaf bin Abdul Aziz — said: “The CRC exists to support constitutional pro-Union causes.

“We were delighted that one such cause we’ve been able to support was the DUP’s Leave campaign.”